Answer:

Step-by-step explanation:
Since we know we only have 640 feet of fence available, we know that L + W + L = 640,
2L + W = 640. This allows us to represent the width, W, in terms of L: W = 640 – 2L
Remember, the area of a rectangle is equal to the product of its width and length, therefore,
Notice that, quadratic has been vertically reflected, since the coefficient on the squared term is negative, so the graph will open downwards, and the vertex will be a maximum value for the area.
recall,
Since our function is A(L)=640L-2L², we get
plug in the value of a and b into the first formula:


hence,the dimensions of the pen that will maximize the area are<u> </u><u>L=</u><u>1</u><u>6</u><u>0</u><u>m</u><u> </u>and<u> </u><u>W=</u><u>7</u><u>6</u><u>8</u><u>0</u><u>0</u><u>/</u><u>1</u><u>6</u><u>0</u><u>=</u><u>4</u><u>8</u><u>0</u><u>m</u>
and we're done!
Answer:the number of coach tickets that she bought is 5
the number of first class tickets that she bought is 6
Step-by-step explanation:
Let x represent the number of coach tickets that she bought.
Let y represent the number of first class tickets that she bought.
The total number of people that went for the round trip is 11. This means that
x + y = 11
She was able to purchase coach tickets for $340 and first class tickets for $1190. She used her total budget for airfare for the trip, which was $8840. This means that
340x + 1190y = 8840 - - - - - - - 1
Substituting x = 11 - y into equation 1, it becomes
340(11-y) + 1190y = 8840
3740 - 340y + 1190y = 8840
- 340y + 1190y = 8840 - 3740
850y = 5100
y = 5100/850 = 6
x = 11 - y
x = 11 - 6 = 5